This is exactly one of the reasons why the view model is passed with a default value. In the preview, you can pass a test object: @Preview @Composable private fun HomeScreenPreview() { val viewModel = HomeViewModel() // setup viewModel as you need it to be in the preview HomeScreen(viewModel = viewModel, navigateToDetailsAction = {}, openCardDetailsAction … Read more
This is precisely what navigation graph scoped view models are used for. This involves two steps: Finding the NavBackStackEntry associated with the graph you want to scope the ViewModel to Pass that to viewModel(). For part 1), you have two options. If you know the route of the navigation graph (which, in general, you should), … Read more
I use lifecycle-extensions 2.2.0 version: implementation “androidx.lifecycle:lifecycle-extensions:2.2.0” It should work, using ViewModelProvider constructor. // With ViewModelFactory val viewModel = ViewModelProvider(this, YourViewModelFactory).get(YourViewModel::class.java) //Without ViewModelFactory val viewModel = ViewModelProvider(this).get(YourViewModel::class.java) 2020/5/15 Update I found another elegant way to achieve this, Android KTX can help implementation “androidx.fragment:fragment-ktx:1.2.4” val viewmodel: MYViewModel by viewModels() val viewmodel: MYViewModel by viewModels { myFactory … Read more
I`m using this EventWraper class from Google Samples inside MutableLiveData /** * Used as a wrapper for data that is exposed via a LiveData that represents an event. */ public class Event<T> { private T mContent; private boolean hasBeenHandled = false; public Event( T content) { if (content == null) { throw new IllegalArgumentException(“null values … Read more
AndroidViewModel provides Application context If you need to use context inside your Viewmodel you should use AndroidViewModel (AVM), because it contains the application context. To retrieve the context call getApplication(), otherwise use the regular ViewModel (VM). AndroidViewModel has application context. We all know having static context instance is evil as it can cause memory leaks!! … Read more
I don’t think there is any best practice as such recommended by android for this. I would suggest you to use the approach which uses cleaner & less boilerplate code. If you are using android data binding along with LiveData you can go with the following approach: Your POJO object would look something like this … Read more